CARNEGIE MELLON UNIVERSITY

09-105 Introduction to Modern Chemistry

Quiz #8

November 19, 1998

Name

Cobalt (III) forms octahedral complexes with coordination number 6. Sketch the structures of all the complex ion's isomers that would be found associated with the neutral compound Co(H₂O)Cl₂(NH₃)₃F using the frames below. More than enough might have been provided. Use the back if more are needed. (You need not have done all, an unreasonable task it turns out.)

Geometrical Isomers

For each of the structural isomers below, there are possibilities of a variety of geometrical isomers. Some examples involving [Co(H2O)Cl2(NH3)3]+ , for example, are where the two Cl's are "trans" vs when they are "cis" to each other; in the latter case when the water is trans to one Cl vs when it is cis to both. You need not present too many of the variety of possibilities to get full credit. (There are too many geometrical isomers here.) (1 point each up to a total of 5 points)

Structural Isomers

The structural isomers that are possible are any arrangements of the following types of species: [Co(H2O)Cl2(NH3)3]+ F- [Co(H2O)ClF(NH3)3]+ Cl- [CoCl2(NH3)3F].H2O (1 point each)

Optical isomers

There is a pair of optical isomers. (2 points)